Thanks for your answer but that is not what i was looking for, probably the way i framed the question.

I have a list of over 30,000 customer numbers, i want to create 3 separate groups (not set) with each having at least over 1000 customers in them. i was able to create sets but not groups because you can copy and paste the list of customer numbers into sets but you cant do that with a group.

Please find my solution below by grouping cust No into 3 groups, but you can change based on your own, just need change the % 3 into % n, n is the number of groups. Any new cust no coming, will be distributed to these groups automatically without any copy/paste or override calculation.

I can't attached back your workbook since it is too big. but let me know if you have quesiton

I'm afraid this doesn't work for me. The customer numbers in each group are random customers and not in sequence.

The group is based on different factors and criteria and sometimes you have customer numers appearing in more than one group or all groups.

Your solution above seems to work but i want to decide what customer number goes into what group. for example, if i want to set up a new group with 508 customer numbers how can i achieve this. Please note, i am able to create a set easily but not a group. or is there a way to turn a set into a group?

Please feel free to delete records in the workbook if you need to reduce the size